Hi Tom, On Thu, 15 May 2025 at 21:54, Tom Rini <tr...@konsulko.com> wrote: > > On Thu, May 15, 2025 at 09:26:42PM +0200, Simon Glass wrote: > > Hi Tom, > > > > On Wed, 14 May 2025 at 23:58, Tom Rini <tr...@konsulko.com> wrote: > > > > > > On Sat, May 10, 2025 at 03:42:07PM +0200, Simon Glass wrote: > > > > > > > Accept a bloblist and control devicetree from a previous phase in > > > > registers 0 to 3, as documented in the Firmware Handoff > > > > specification[1]. > > > > > > > > Note that there is currently a weak function called save_boot_params() > > > > which happens to save the same registers as are needed for this > > > > protocol. But it seems better to implement this feature as a first-class > > > > citizen, if for no other reason than that many boards have their own > > > > version of save_boot_params() which may not happen to save the required > > > > registers. A weak function is not a good basis for an API. > > > > > > > > [1] https://firmwarehandoff.github.io/firmware_handoff/main/index.html > > > > > > > > Signed-off-by: Simon Glass <s...@chromium.org> > > > > --- > > > > While some efforts were made to encourage Intel to adopt this > > > > specification, this has not yet been successful. However I do intend to > > > > use my proposed x86 handoff in U-Boot, once this series is in. > > > > > > > > Changes in v4: > > > > - Update commit message to indicate this can only be for ARM at present > > > > - Update commit message to mention why save_boot_params() is not used > > > > > > > > Changes in v3: > > > > - Add support for aarch64 also > > > > - Update registers to match the Firmware Handoff protocol > > > > > > > > Changes in v2: > > > > - Use three registers instead of two for the entry > > > > > > > > arch/arm/cpu/armv7/start.S | 10 +++++++++- > > > > arch/arm/cpu/armv8/start.S | 12 ++++++++++++ > > > > arch/arm/lib/crt0.S | 6 ++++++ > > > > arch/arm/lib/crt0_64.S | 6 ++++++ > > > > 4 files changed, 33 insertions(+), 1 deletion(-) > > > > > > This is what makes me think you aren't actually working on my feedback > > > about taking what we have in-tree, now, rather than just forward porting > > > your old series and deleting the current code. > > > > Well, yes, I sent this v3 series because I had thought you were > > willing to allow me to maintain bloblist. I certainly appreciate the > > work in this area, though. > > > > > > > > We have save_boot_params doing exactly what it should today, including > > > saving off a standard passage and making what was saved available later, > > > in an intentional fashion. If, hypothetically, Pi needs to override > > > save_boot_param because a future new-firmware-blob does standard passage > > > but at run time we want to support both, that's a good thing. > > > > > > With commit ea3348ebc215 ('Merge patch series "Handoff bloblist from > > > previous boot stage"') we already implement the specification in [1]. It > > > is not a "which happens to". It is intentional. > > > > > > I guess the overall challenge here is that you want to do things which > > > are a superset of the firmware handoff spec itself? > > > > Yes,, much of this series relates to putting some structure into > > things which are passed via standard passage, including validation. > > > > I actually don't understand why you would be keen on using > > save_boot_params(), a weak function, used for board-specific features, > > to implement standard passage. We should build standard passage in as > > a first-class citizen. I certainly don't want to try to implement > > things that way on x86. > > You seem to have misunderstood a lot of things and perhaps need to go > and re-read the feedback. Nothing about a weak function implies less > than "first class" and "maintain the code" does not equate "delete and > replace functional code with the same thing, but I wrote it". And if you > aren't going to do that, please don't bother posting a v4 either later > this week. I feel like I'm having zero progress with you taking my > feedback on anything at this point.
Are you completely set on the idea of a weak function here? Regards, SImon
